Overconsumption of foods that result from extensive industrial processing is believed to contribute to the development of obesity. Ultra-processed foods now represent most of the calories consumed in America and their contribution to overall diet has increased in parallel with the rise in the prevalence of obesity over the past several decades. While such correlations are suggestive, the effect of industrial processing per se, independent of dietary macronutrient composition, on ad libitum energy intake has not been carefully investigated. Therefore, we have initiated a feeding study in 20 adult men and women to investigate the differences in ad libitum energy intake resulting from consuming two test diets for a pair of 2-week periods in a randomized, crossover design during a single 4-week period. The test diets presented to participants will be matched for calories, macronutrient composition, sugar, fiber, and sodium, but one diet will be composed of ultra-processed foods whereas the other diet will be unprocessed foods.